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Perdikari A, Woods VA, Ebrahim A, Lawler K, Bounds R, Singh NI, Mehlman TS, Riley BT, Sharma S, Morris JW, Keogh JM, Henning E, Smith M, Farooqi IS, Keedy DA. Structures of human PTP1B variants reveal allosteric sites to target for weight loss therapy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.05.603709. [PMID: 39149290 PMCID: PMC11326154 DOI: 10.1101/2024.08.05.603709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Protein Tyrosine Phosphatase 1B (PTP1B) is a negative regulator of leptin signaling whose disruption protects against diet-induced obesity in mice. We investigated whether structural characterization of human PTP1B variant proteins might reveal precise mechanisms to target for weight loss therapy. We selected 12 rare variants for functional characterization from exomes from 997 people with persistent thinness and 200,000 people from UK Biobank. Seven of 12 variants impaired PTP1B function by increasing leptin-stimulated STAT3 phosphorylation in cells. Using room-temperature X-ray crystallography, hydrogen-deuterium exchange mass spectrometry, and computational modeling, we determined that human variants modulate the 3-dimensional structure of PTP1B through distinct allosteric conduits that energetically link distal, highly ligandable structural regions to the active site. These studies inform the design of allosteric PTP1B inhibitors for the treatment of obesity.
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Oliver H, Ruta D, Thompson D, Kamli-Salino S, Philip S, Wilson HM, Mody N, Delibegovic M. Myeloid PTP1B deficiency protects against atherosclerosis by improving cholesterol homeostasis through an AMPK-dependent mechanism. J Transl Med 2023; 21:715. [PMID: 37828508 PMCID: PMC10568790 DOI: 10.1186/s12967-023-04598-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 10/06/2023] [Indexed: 10/14/2023] Open
Abstract
OBJECTIVE Atherosclerosis is a chronic inflammatory process induced by the influx and entrapment of excess lipoproteins into the intima media of arteries. Previously, our lab demonstrated that systemic PTP1B inhibition protects against atherosclerosis in preclinical LDLR-/- models. Similarly, it was shown that myeloid-specific PTP1B ablation decreases plaque formation and ameliorates dyslipidaemia in the ApoE-/- model of atherosclerosis. We hypothesized that the relevant improvements in dyslipidaemia following modification of PTP1B activation may either result from changes in hepatic cholesterol biosynthesis and/or increased uptake and degradation by liver-resident macrophages. We examined this in animal models and patients with coronary artery disease. METHODS In this study, we determined the cholesterol-lowering effect of myeloid-PTP1B deletion in mice fed a high-fat high-cholesterol diet and examined effects on total cholesterol levels and lipoprotein profiles. We also determined the effects of PTP1B inhibition to oxLDL-C challenge on foam cell formation and cholesterol efflux in human monocytes/macrophages. RESULTS We present evidence that myeloid-PTP1B deficiency significantly increases the affinity of Kupffer cells for ApoB containing lipoproteins, in an IL10-dependent manner. We also demonstrate that PTP1B inhibitor, MSI-1436, treatment decreased foam cell formation in Thp1-derived macrophages and increased macrophage cholesterol efflux to HDL in an AMPK-dependent manner. We present evidence of three novel and distinct mechanisms regulated by PTP1B: an increase in cholesterol efflux from foam cells, decreased uptake of lipoproteins into intra-lesion macrophages in vitro and a decrease of circulating LDL-C and VLDL-C in vivo. CONCLUSIONS Overall, these results suggest that myeloid-PTP1B inhibition has atheroprotective effects through improved cholesterol handling in atherosclerotic lesions, as well as increased reverse cholesterol transport. Trial registration Research registry, researchregistry 3235. Registered 07 November 2017, https://www.researchregistry.com/browse-the-registry#home/registrationdetails/5a01d0fce7e1904e93e0aac5/ .
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Affiliation(s)
- Helk Oliver
- Aberdeen Cardiovascular and Diabetes Centre, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
- Department of Medicine III, Division of Nephrology and Dialysis, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
| | - Dekeryte Ruta
- Aberdeen Cardiovascular and Diabetes Centre, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Dawn Thompson
- Aberdeen Cardiovascular and Diabetes Centre, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Sarah Kamli-Salino
- Aberdeen Cardiovascular and Diabetes Centre, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Sam Philip
- Aberdeen Cardiovascular and Diabetes Centre, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
- Grampian Diabetes Research Unit, JJR Macleod Centre, NHS Grampian, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Heather M Wilson
- Aberdeen Cardiovascular and Diabetes Centre, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Nimesh Mody
- Aberdeen Cardiovascular and Diabetes Centre, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Mirela Delibegovic
- Aberdeen Cardiovascular and Diabetes Centre, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
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Association between PTPN1 polymorphisms and obesity-related phenotypes in European adolescents: influence of physical activity. Pediatr Res 2022:10.1038/s41390-022-02377-1. [PMID: 36369476 DOI: 10.1038/s41390-022-02377-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/06/2022] [Accepted: 10/23/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND To study the associations of Protein Tyrosine Phosphatase-N1 (PTPN1) polymorphisms with obesity-related phenotypes in European adolescents, and the influence of physical activity on these relationships. METHODS Five polymorphisms of PTPN1 were genotyped in 1057 European adolescents (12-18 years old). We measured several phenotypes related to obesity, such as adiposity markers, and biochemical and clinical parameters. Physical activity was objectively measured by accelerometry. RESULTS The T, A, T, T and G alleles of the rs6067472, rs10485614, rs2143511, rs6020608 and rs968701 polymorphisms, respectively, were associated with lower levels of obesity-related phenotypes (i.e., body mass index, body fat percentage, hip circumference, fat mass index, systolic blood pressure and leptin) in European adolescents. In addition, the TATTG haplotype was associated with lower body fat percentage and fat mass index compared to the AACCA haplotype. Finally, when physical activity levels were considered, alleles of the rs6067472, rs2143511, rs6020608 and rs968701 polymorphisms were only associated with lower adiposity in active adolescents. CONCLUSIONS PTPN1 polymorphisms were associated with adiposity in European adolescents. Specifically, alleles of these polymorphisms were associated with lower adiposity only in physically active adolescents. Therefore, meeting the recommendations of daily physical activity may reduce obesity risk by modulating the genetic predisposition to obesity. IMPACT Using gene-phenotype and gene*environment analyses, we detected associations between polymorphisms of the Protein Tyrosine Phosphatase-N1 (PTPN1) gene and obesity-related phenotypes, suggesting a mechanism that can be modulated by physical activity. This study shows that genetic variability of PTPN1 is associated with adiposity, while physical activity seems to modulate the genetic predisposition. This brings insights about the mechanisms by which physical activity positively influences obesity.
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Beddows CA, Dodd GT. Insulin on the brain: The role of central insulin signalling in energy and glucose homeostasis. J Neuroendocrinol 2021; 33:e12947. [PMID: 33687120 DOI: 10.1111/jne.12947] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 12/26/2022]
Abstract
Insulin signals to the brain where it coordinates multiple physiological processes underlying energy and glucose homeostasis. This review explores where and how insulin interacts within the brain parenchyma, how brain insulin signalling functions to coordinate energy and glucose homeostasis and how this contributes to the pathogenesis of metabolic disease.
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Affiliation(s)
- Cait A Beddows
- Department of Anatomy and Physiology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Garron T Dodd
- Department of Anatomy and Physiology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
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Therapeutic Role of Protein Tyrosine Phosphatase 1B in Parkinson's Disease via Antineuroinflammation and Neuroprotection In Vitro and In Vivo. PARKINSONS DISEASE 2020; 2020:8814236. [PMID: 33456749 PMCID: PMC7787797 DOI: 10.1155/2020/8814236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/18/2020] [Accepted: 12/11/2020] [Indexed: 12/18/2022]
Abstract
Parkinson's disease (PD) is one of the most widespread neurodegenerative diseases. However, the currently available treatments could only relieve symptoms. Novel therapeutic targets are urgently needed. Several previous studies mentioned that protein tyrosine phosphatase 1B (PTP1B) acted as a negative regulator of the insulin signal pathway and played a significant role in the inflammation process. However, few studies have investigated the role of PTP1B in the central nervous system. Our study showed that suramin, an inhibitor of PTP1B, could improve neuronal damage. It could significantly attenuate the interferon-gamma-induced upregulation of proinflammatory cytokines, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). It enhanced M2 type microglia markers, such as arginase-1 and Ym-1 in BV2 murine microglial cells. PTP1B inhibition also reversed 6-hydroxydopamine- (6-OHDA-) induced downregulation of phospho-cAMP response element-binding protein (p-CREB) and brain-derived neurotrophic factor (BDNF) in SH-SY5Y cells. Besides, we knocked down and overexpressed PTP1B in the SH-SY5Y cells to confirm its role in neuroprotection. We also verified the effect of suramin in the zebrafish PD model. Treatment with suramin could significantly reverse 6-OHDA-induced locomotor deficits and improved tyrosine hydroxylase (TH) via attenuating endoplasmic reticulum (ER) stress biomarkers. These results support that PTP1B could potentially regulate PD via antineuroinflammation and antiapoptotic pathways.
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Feng CW, Chen NF, Chan TF, Chen WF. Therapeutic Role of Protein Tyrosine Phosphatase 1B in Parkinson's Disease via Antineuroinflammation and Neuroprotection In Vitro and In Vivo. PARKINSON'S DISEASE 2020. [PMID: 33456749 DOI: 10.1155/2020/8814236.ecollection2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
Abstract
Parkinson's disease (PD) is one of the most widespread neurodegenerative diseases. However, the currently available treatments could only relieve symptoms. Novel therapeutic targets are urgently needed. Several previous studies mentioned that protein tyrosine phosphatase 1B (PTP1B) acted as a negative regulator of the insulin signal pathway and played a significant role in the inflammation process. However, few studies have investigated the role of PTP1B in the central nervous system. Our study showed that suramin, an inhibitor of PTP1B, could improve neuronal damage. It could significantly attenuate the interferon-gamma-induced upregulation of proinflammatory cytokines, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). It enhanced M2 type microglia markers, such as arginase-1 and Ym-1 in BV2 murine microglial cells. PTP1B inhibition also reversed 6-hydroxydopamine- (6-OHDA-) induced downregulation of phospho-cAMP response element-binding protein (p-CREB) and brain-derived neurotrophic factor (BDNF) in SH-SY5Y cells. Besides, we knocked down and overexpressed PTP1B in the SH-SY5Y cells to confirm its role in neuroprotection. We also verified the effect of suramin in the zebrafish PD model. Treatment with suramin could significantly reverse 6-OHDA-induced locomotor deficits and improved tyrosine hydroxylase (TH) via attenuating endoplasmic reticulum (ER) stress biomarkers. These results support that PTP1B could potentially regulate PD via antineuroinflammation and antiapoptotic pathways.
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Affiliation(s)
- Chien-Wei Feng
- Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Kaohsiung 807377, Taiwan
- Center for Cancer Research, Kaohsiung Medical University, Kaohsiung 807377, Taiwan
| | - Nan-Fu Chen
- Division of Neurosurgery, Department of Surgery, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan
| | - Te-Fu Chan
- Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Kaohsiung 807377, Taiwan
- Center for Cancer Research, Kaohsiung Medical University, Kaohsiung 807377, Taiwan
| | - Wu-Fu Chen
- Department of Neurosurgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
- Department of Neurosurgery, Xiamen Chang Gung Hospital, Xiamen, Fujian, China
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
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Izquierdo AG, Crujeiras AB, Casanueva FF, Carreira MC. Leptin, Obesity, and Leptin Resistance: Where Are We 25 Years Later? Nutrients 2019; 11:nu11112704. [PMID: 31717265 PMCID: PMC6893721 DOI: 10.3390/nu11112704] [Citation(s) in RCA: 260] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/27/2019] [Accepted: 10/31/2019] [Indexed: 12/14/2022] Open
Abstract
Leptin, a hormone that is capable of effectively reducing food intake and body weight, was initially considered for use in the treatment of obesity. However, obese subjects have since been found to have high levels of circulating leptin and to be insensitive to the exogenous administration of leptin. The inability of leptin to exert its anorexigenic effects in obese individuals, and therefore, the lack of clinical utility of leptin in obesity, is defined as leptin resistance. This phenomenon has not yet been adequately characterized. Elucidation of the molecular mechanisms underlying leptin resistance is of vital importance for the application of leptin as an effective treatment for obesity. Leptin must cross the blood–brain barrier (BBB) to reach the hypothalamus and exert its anorexigenic functions. The mechanisms involved in leptin transportation across the blood–brain barrier continue to be unclear, thereby preventing the clinical application of leptin in the treatment of obesity. In recent years, new strategies have been developed to recover the response to leptin in obesity. We have summarized these strategies in this review.
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Affiliation(s)
- Andrea G. Izquierdo
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Ana B. Crujeiras
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Felipe F. Casanueva
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Molecular Endocrinolgy, Universidad de Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
| | - Marcos C. Carreira
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
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8
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Effects of thyroid hormones and cold acclimation on the energy metabolism of the striped hamster (Cricetulus barabensis). J Comp Physiol B 2019; 189:153-165. [DOI: 10.1007/s00360-018-1197-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/11/2018] [Accepted: 12/07/2018] [Indexed: 02/07/2023]
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9
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Nilaweera KN, Speakman JR. Regulation of intestinal growth in response to variations in energy supply and demand. Obes Rev 2018; 19 Suppl 1:61-72. [PMID: 30511508 PMCID: PMC6334514 DOI: 10.1111/obr.12780] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 12/14/2022]
Abstract
The growth of the intestine requires energy, which is known to be met by catabolism of ingested nutrients. Paradoxically, during whole body energy deficit including calorie restriction, the intestine grows in size. To understand how and why this happens, we reviewed data from several animal models of energetic challenge. These were bariatric surgery, cold exposure, lactation, dietary whey protein intake and calorie restriction. Notably, these challenges all reduced the adipose tissue mass, altered hypothalamic neuropeptide expression and increased intestinal size. Based on these data, we propose that the loss of energy in the adipose tissue promotes the growth of the intestine via a signalling mechanism involving the hypothalamus. We discuss possible candidates in this pathway including data showing a correlative change in intestinal (ileal) expression of the cyclin D1 gene with adipose tissue mass, adipose derived-hormone leptin and hypothalamic expression of leptin receptor and the pro-opiomelanocortin gene. The ability of the intestine to grow in size during depletion of energy stores provides a mechanism to maximize assimilation of ingested energy and in turn sustain critical functions of tissues important for survival.
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Affiliation(s)
- K N Nilaweera
- Department of Food Biosciences, Teagasc Food Research Centre, Fermoy, County Cork, Ireland
| | - J R Speakman
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
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Laperrousaz E, Denis RG, Kassis N, Contreras C, López M, Luquet S, Cruciani-Guglielmacci C, Magnan C. Lipoprotein Lipase Expression in Hypothalamus Is Involved in the Central Regulation of Thermogenesis and the Response to Cold Exposure. Front Endocrinol (Lausanne) 2018; 9:103. [PMID: 29593657 PMCID: PMC5861133 DOI: 10.3389/fendo.2018.00103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/02/2018] [Indexed: 11/15/2022] Open
Abstract
Lipoprotein lipase (LPL) is expressed in different areas of the brain, including the hypothalamus and plays an important role in neural control of the energy balance, including feeding behavior and metabolic fluxes. This study tested the hypothesis that hypothalamic LPL participates in the control of body temperature. We first showed that cold exposure induces decreased activity and expression of LPL in the mouse hypothalamus. We then selectively deleted LPL in the mediobasal hypothalamus (MBH) through an adeno-associated virus approach in LPL-floxed mice and generated MBHΔ Lpl mice with 30-35% decrease in hypothalamic LPL activity. Results showed a decrease in body temperature in MBHΔ Lpl mice when compared with controls at 22°C. Exposure to cold (4°C for 4 h) decreased the body temperature of the control mice while that of the MBHΔ Lpl mice remained similar to that observed at 22°C. MBHΔ Lpl mice also showed increased energy expenditure during cold exposure, when compared to controls. Finally, the selective MBH deletion of LPL also increased the expression of the thermogenic PRMD16 and Dio2 in subcutaneous and perigonadal adipose tissues. Thus, the MBH LPL deletion seems to favor thermogenesis. These data demonstrate that for the first time hypothalamic LPL appears to function as a regulator of body temperature and cold-induced thermogenesis.
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Affiliation(s)
- Elise Laperrousaz
- Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Sorbonne Paris Cité, Université Denis Diderot, Paris, France
| | - Raphaël G Denis
- Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Sorbonne Paris Cité, Université Denis Diderot, Paris, France
| | - Nadim Kassis
- Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Sorbonne Paris Cité, Université Denis Diderot, Paris, France
| | - Cristina Contreras
- NeurObesity Group, Department of Physiology, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CiMUS), University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - Miguel López
- NeurObesity Group, Department of Physiology, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CiMUS), University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - Serge Luquet
- Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Sorbonne Paris Cité, Université Denis Diderot, Paris, France
| | - Céline Cruciani-Guglielmacci
- Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Sorbonne Paris Cité, Université Denis Diderot, Paris, France
| | - Christophe Magnan
- Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Sorbonne Paris Cité, Université Denis Diderot, Paris, France
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Townsend KL, Madden CJ, Blaszkiewicz M, McDougall L, Tupone D, Lynes MD, Mishina Y, Yu P, Morrison SF, Tseng YH. Reestablishment of Energy Balance in a Male Mouse Model With POMC Neuron Deletion of BMPR1A. Endocrinology 2017; 158:4233-4245. [PMID: 29040444 PMCID: PMC5711385 DOI: 10.1210/en.2017-00212] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 10/04/2017] [Indexed: 11/19/2022]
Abstract
The regulation of energy balance involves complex processes in the brain, including coordination by hypothalamic neurons that contain pro-opiomelanocortin (POMC). We previously demonstrated that central bone morphogenetic protein (BMP) 7 reduced appetite. Now we show that a type 1 BMP receptor, BMPR1A, is colocalized with POMC neurons and that POMC-BMPR1A-knockout (KO) mice are hyperphagic, revealing physiological involvement of BMP signaling in anorectic POMC neurons in the regulation of appetite. Surprisingly, the hyperphagic POMC-BMPR1A-KO mice exhibited a lack of obesity, even on a 45% high-fat diet. This is because the brown adipose tissue (BAT) of KO animals exhibited increased sympathetic activation and greater thermogenic capacity owing to a reestablishment of energy balance, most likely stemming from a compensatory increase of BMPR1A in the whole hypothalamus of KO mice. Indeed, control animals given central BMP7 displayed increased energy expenditure and a specific increase in sympathetic nerve activity (SNA) in BAT. In these animals, pharmacological blockade of BMPR1A-SMAD signaling blunted the ability of BMP7 to increase energy expenditure or BAT SNA. Together, we demonstrated an important role for hypothalamic BMP signaling in the regulation of energy balance, including BMPR1A-mediated appetite regulation in POMC neurons as well as hypothalamic BMP-SMAD regulation of the sympathetic drive to BAT for thermogenesis.
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Affiliation(s)
- Kristy L Townsend
- Integrative Physiology and Metabolism Section, Joslin Diabetes Center, Harvard Medical School
- School of Biology and Ecology and Graduate School of Biomedical Sciences and Engineering, University of Maine
| | | | - Magdalena Blaszkiewicz
- School of Biology and Ecology and Graduate School of Biomedical Sciences and Engineering, University of Maine
| | - Lindsay McDougall
- Integrative Physiology and Metabolism Section, Joslin Diabetes Center, Harvard Medical School
| | - Domenico Tupone
- Department of Neurological Surgery, Oregon Health & Science University
| | - Matthew D Lynes
- Integrative Physiology and Metabolism Section, Joslin Diabetes Center, Harvard Medical School
| | | | - Paul Yu
- Brigham and Women's Hospital and Harvard Medical School
| | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University
| | - Yu-Hua Tseng
- Integrative Physiology and Metabolism Section, Joslin Diabetes Center, Harvard Medical School
- Harvard Stem Cell Institute, Harvard University
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Tham SW, Li L, Effraim P, Waxman S. Between fire and ice: refractory hypothermia and warmth-induced pain in inherited erythromelalgia. BMJ Case Rep 2017; 2017:bcr-2017-219486. [PMID: 28751508 DOI: 10.1136/bcr-2017-219486] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Inherited erythromelalgia (IEM) is a well-described pain disorder caused by mutations of sodium channel Nav1.7, a peripheral channel expressed within dorsal root ganglion and the sympathetic ganglion neurons. Clinically, IEM is characterised by paroxysmal attacks of severe pain, usually in the distal extremities, triggered by warmth or exercise. Pain is not adequately treated by existing pharmacological agents. Individuals with IEM classically cool their limbs for relief, in some cases resulting in tissue injury. We describe a patient from a family with IEM due to the L858F mutation of Nav1.7 who presented with refractory hypothermia due to overcooling. This presentation of refractory hypothermia necessitating warming strategies, complicated by severe warmth-induced pain, posed a substantial therapeutic challenge. We report our experience in overcoming hypothermia lasting 3 weeks in a child with IEM, discuss possible pathophysiological mechanisms underlying this unusual complication and suggest potential therapeutic interventions.
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Affiliation(s)
- See Wan Tham
- Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Anesthesia and Pain Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Li Li
- Department of Anesthesia and Pain Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Philip Effraim
- Department of Anesthesia, Yale University School of Medicine, New Haven, Connecticut, USA.,Center for Neuroscience and Regeneration Research, Yale University School of Medicine, Veteran Affairs Medical Center, West Haven, Connecticut, USA
| | - Stephen Waxman
- Center for Neuroscience and Regeneration Research, Yale University School of Medicine, Veteran Affairs Medical Center, West Haven, Connecticut, USA.,Department of Neurology, Yale University School of Medicine, West Haven, Connecticut, USA
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13
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Jais A, Brüning JC. Hypothalamic inflammation in obesity and metabolic disease. J Clin Invest 2017; 127:24-32. [PMID: 28045396 DOI: 10.1172/jci88878] [Citation(s) in RCA: 289] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Over the last years, hypothalamic inflammation has been linked to the development and progression of obesity and its sequelae. There is accumulating evidence that this inflammation not only impairs energy balance but also contributes to obesity-associated insulin resistance. Elevated activation of key inflammatory mediators such as JNK and IκB kinase (IKK) occurs rapidly upon consumption of a high-fat diet, even prior to significant weight gain. This activation of hypothalamic inflammatory pathways results in the uncoupling of caloric intake and energy expenditure, fostering overeating and further weight gain. In addition, these inflammatory processes contribute to obesity-associated insulin resistance and deterioration of glucose metabolism via altered neurocircuit functions. An understanding of the contributions of different neuronal and non-neuronal cell types to hypothalamic inflammatory processes, and delineation of the differences and similarities between acute and chronic activation of these inflammatory pathways, will be critical for the development of novel therapeutic strategies for the treatment of obesity and metabolic syndrome.
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14
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Gibson LC, Shin BC, Dai Y, Freije W, Kositamongkol S, Cho J, Devaskar SU. Early leptin intervention reverses perturbed energy balance regulating hypothalamic neuropeptides in the pre- and postnatal calorie-restricted female rat offspring. J Neurosci Res 2015; 93:902-12. [PMID: 25639584 PMCID: PMC4533910 DOI: 10.1002/jnr.23560] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/05/2014] [Accepted: 12/24/2014] [Indexed: 12/16/2022]
Abstract
Pre- and postnatal calorie restriction is associated with postnatal growth restriction, reduced circulating leptin concentrations, and perturbed energy balance. Hypothalamic regulation of energy balance demonstrates enhanced orexigenic (NPY, AgRP) and diminished anorexigenic (POMC, CART) neuropeptide expression (PN21), setting the stage for subsequent development of obesity in female Sprague-Dawley rats. Leptin replenishment during the early postnatal period (PN2-PN8) led to reversal of the hypothalamic orexigenic:anorexigenic neuropeptide ratio at PN21 by reducing only the orexigenic (NPY, AgRP), without affecting the anorexigenic (POMC, CART) neuropeptide expression. This hypothalamic effect was mediated via enhanced leptin receptor (ObRb) signaling that involved increased pSTAT3/STAT3 but reduced PTP1B. This was further confirmed by an increase in body weight at PN21 in response to intracerebroventricular administration of antisense ObRb oligonucleotides (PN2-PN8). The change in the hypothalamic neuropeptide balance in response to leptin administration was associated with increased oxygen consumption, carbon dioxide production, and physical activity, which resulted in increased milk intake (PN14) with no change in body weight. This is in contrast to the reduction in milk intake with no effect on energy expenditure and physical activity observed in controls. We conclude that pre- and postnatal calorie restriction perturbs hypothalamic neuropeptide regulation of energy balance, setting the stage for hyperphagia and reduced energy expenditure, hallmarks of obesity. Leptin in turn reverses this phenotype by increasing hypothalamic ObRb signaling (sensitivity) and affecting only the orexigenic arm of the neuropeptide balance.
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Affiliation(s)
- Leena Caroline Gibson
- Department of Pediatrics, Division of Neonatology & Developmental Biology and Neonatal Research Center at the UCLA Children’s Discovery and Innovation Institute, Los Angeles, CA 90095-1752
| | - Bo-Chul Shin
- Department of Pediatrics, Division of Neonatology & Developmental Biology and Neonatal Research Center at the UCLA Children’s Discovery and Innovation Institute, Los Angeles, CA 90095-1752
| | - Yun Dai
- Department of Pediatrics, Division of Neonatology & Developmental Biology and Neonatal Research Center at the UCLA Children’s Discovery and Innovation Institute, Los Angeles, CA 90095-1752
| | - William Freije
- Department of Obstetrics and Gynecology, David Geffen School of Medicine UCLA, Los Angeles, CA 90095-1752
| | - Sudatip Kositamongkol
- Department of Pediatrics, Division of Neonatology & Developmental Biology and Neonatal Research Center at the UCLA Children’s Discovery and Innovation Institute, Los Angeles, CA 90095-1752
| | - John Cho
- Department of Pediatrics, Division of Neonatology & Developmental Biology and Neonatal Research Center at the UCLA Children’s Discovery and Innovation Institute, Los Angeles, CA 90095-1752
| | - Sherin U. Devaskar
- Department of Pediatrics, Division of Neonatology & Developmental Biology and Neonatal Research Center at the UCLA Children’s Discovery and Innovation Institute, Los Angeles, CA 90095-1752
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15
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Kandadi MR, Panzhinskiy E, Roe ND, Nair S, Hu D, Sun A. Deletion of protein tyrosine phosphatase 1B rescues against myocardial anomalies in high fat diet-induced obesity: Role of AMPK-dependent autophagy. Biochim Biophys Acta Mol Basis Dis 2015; 1852:299-309. [DOI: 10.1016/j.bbadis.2014.07.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 06/20/2014] [Accepted: 07/03/2014] [Indexed: 01/11/2023]
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16
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Young CN, Morgan DA, Butler SD, Rahmouni K, Gurley SB, Coffman TM, Mark AL, Davisson RL. Angiotensin type 1a receptors in the forebrain subfornical organ facilitate leptin-induced weight loss through brown adipose tissue thermogenesis. Mol Metab 2015; 4:337-43. [PMID: 25830096 PMCID: PMC4354922 DOI: 10.1016/j.molmet.2015.01.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 01/21/2015] [Accepted: 01/23/2015] [Indexed: 11/15/2022] Open
Abstract
Objective Elevations in brain angiotensin-II cause increased energy expenditure and a lean phenotype. Interestingly, the metabolic effects of increased brain angiotensin-II mimic the actions of leptin, suggesting an interaction between the two systems. Here we demonstrate that angiotensin-type 1a receptors (AT1aR) in the subfornical organ (SFO), a forebrain structure emerging as an integrative metabolic center, play a key role in the body weight-reducing effects of leptin via brown adipose tissue (BAT) thermogenesis. Methods Cre/LoxP technology coupled with targeted viral delivery to the SFO in a mouse line bearing a conditional allele of the Agtr1a gene was utilized to determine the interaction between leptin and SFO AT1aR in metabolic regulation. Results Selective deletion of AT1aR in the SFO attenuated leptin-induced weight loss independent of changes in food intake or locomotor activity. This was associated with diminished leptin-induced increases in core body temperature, blunted upregulation of BAT thermogenic markers, and abolishment of leptin-mediated sympathetic activation to BAT. Conclusions These data identify a novel interaction between angiotensin-II and leptin in the control of BAT thermogenesis and body weight, and highlight a previously unrecognized role for the forebrain SFO in metabolic regulation.
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Affiliation(s)
- Colin N. Young
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Donald A. Morgan
- Department of Pharmacology, University of Iowa, Iowa City, IA, 52242, USA
| | - Scott D. Butler
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Iowa City, IA, 52242, USA
| | - Susan B. Gurley
- Division of Nephrology, Department of Medicine, Duke University, Durham, NC 27710, USA
| | - Thomas M. Coffman
- Division of Nephrology, Department of Medicine, Duke University, Durham, NC 27710, USA
| | - Allyn L. Mark
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
- Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Robin L. Davisson
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY, 10065, USA
- Corresponding author. T9-014C Veterinary Research Tower, Cornell University, Ithaca, NY, 14853-6401, USA. Tel.: +1 607 253 3537; fax: +1 607 253 3378.
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17
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Knobler H, Elson A. Metabolic regulation by protein tyrosine phosphatases. J Biomed Res 2014; 28:157-68. [PMID: 25013399 PMCID: PMC4085553 DOI: 10.7555/jbr.28.20140012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 01/28/2014] [Indexed: 01/14/2023] Open
Abstract
Obesity and the metabolic syndrome and their associated morbidities are major public health issues, whose prevalence will continue to increase in the foreseeable future. Aberrant signaling by the receptors for leptin and insulin plays a pivotal role in development of the metabolic syndrome. More complete molecular-level understanding of how both of these key signaling pathways are regulated is essential for full characterization of obesity, the metabolic syndrome, and type II diabetes, and for developing novel treatments for these diseases. Phosphorylation of proteins on tyrosine residues plays a key role in mediating the effects of leptin and insulin on their target cells. Here, we discuss the molecular methods by which protein tyrosine phosphatases, which are key physiological regulators of protein phosphorylation in vivo, affect signaling by the leptin and insulin receptors in their major target tissues.
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Affiliation(s)
- Hilla Knobler
- Diabetes and Metabolic Disease Unit, Kaplan Medical Center, Rehovot 76100, Israel
| | - Ari Elson
- Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot 76100, Israel
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18
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19
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Tsou RC, Rak KS, Zimmer DJ, Bence KK. Improved metabolic phenotype of hypothalamic PTP1B-deficiency is dependent upon the leptin receptor. Mol Metab 2014; 3:301-12. [PMID: 24749060 PMCID: PMC3986631 DOI: 10.1016/j.molmet.2014.01.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/05/2014] [Accepted: 01/11/2014] [Indexed: 12/14/2022] Open
Abstract
Protein tyrosine phosphatase 1B (PTP1B) is a known regulator of central metabolic signaling, and mice with whole brain-, leptin receptor (LepRb) expressing cell-, or proopiomelanocortin neuron-specific PTP1B-deficiency are lean, leptin hypersensitive, and display improved glucose homeostasis. However, whether the metabolic effects of central PTP1B-deficiency are due to action within the hypothalamus remains unclear. Moreover, whether or not these effects are exclusively due to enhanced leptin signaling is unknown. Here we report that mice with hypothalamic PTP1B-deficiency (Nkx2.1-PTP1B(-/-)) display decreased body weight and adiposity on high-fat diet with no associated improvements in glucose tolerance. Consistent with previous reports, we find that hypothalamic deletion of the LepRb in mice (Nkx2.1-LepRb(-/-)) results in extreme hyperphagia and obesity. Interestingly, deletion of hypothalamic PTP1B and LepRb (Nkx2.1-PTP1B(-/-):LepRb(-/-)) does not rescue the hyperphagia or obesity of Nkx2.1-LepRb(-/-) mice, suggesting that hypothalamic PTP1B contributes to the central control of energy balance through a leptin receptor-dependent pathway.
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Key Words
- BAT, Brown adipose tissue
- CNTF, Ciliary neurotrophic factor
- Cre, Cre recombinase
- GTT, Glucose tolerance test
- HFD, High-fat diet
- HPA, hypothalamus–pituitary–adrenal
- Hypothalamus
- IL-6, Interleukin-6
- ITT, Insulin tolerance test
- JAK2, Janus kinase 2
- LepRb, Leptin receptor long form
- Leptin
- Nkx2.1, NK2 homeobox 1 protein or thyroid transcription factor-1
- Obesity
- PI3K, Phosphatidylinositol 3-kinase
- POMC, Proopiomelanocortin
- PTP1B, Protein tyrosine phosphatase 1B
- PTPs, Protein tyrosine phosphatases
- Phosphatase
- Prdm16, PR domain containing 16
- SHP2, Src homology 2 domain-containing protein tyrosine phosphatase
- STAT3, Signal transducer and activator of transcription 3
- UCP1, Uncoupling protein 1
- WAT, White adipose tissue
- db/db, Leptin receptor-deficient mice
- ob/ob, leptin-deficient mice
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Affiliation(s)
- Ryan C Tsou
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kimberly S Rak
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Derek J Zimmer
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kendra K Bence
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
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20
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Roujeau C, Jockers R, Dam J. New pharmacological perspectives for the leptin receptor in the treatment of obesity. Front Endocrinol (Lausanne) 2014; 5:167. [PMID: 25352831 PMCID: PMC4195360 DOI: 10.3389/fendo.2014.00167] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 09/26/2014] [Indexed: 12/24/2022] Open
Abstract
After its discovery in 1994, leptin became the great hope as an anti-obesity treatment based on its ability to reduce food intake and increase energy expenditure. However, treating obese people with exogenous leptin was unsuccessful in most cases since most of them present already high circulating leptin levels to which they do not respond anymore defining the so-called state of "leptin resistance." Indeed, leptin therapy is unsuccessful to lower body weight in commonly obese people but effective in people with rare single gene mutations of the leptin gene. Consequently, treatment of obese people with leptin was given less attention and the focus of obesity research shifted toward the prevention and reversal of the state of leptin resistance. Many of these new promising approaches aim to restore or sensitize the impaired function of the leptin receptor by pharmacological means. The current review will focus on the different emerging therapeutic strategies in obesity research that are related to leptin and its receptor.
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Affiliation(s)
- Clara Roujeau
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Ralf Jockers
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Julie Dam
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
- *Correspondence: Julie Dam, Institut Cochin, 22 rue Méchain, 75014, Paris, France e-mail:
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21
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Abstract
Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of the leptin and insulin signaling pathways. The important roles of PTP1B related to obesity and diabetes were confirmed by a deletion of PTP1B gene in mice. Mice with the whole body deletion of PTP1B were protected against the development of obesity and diabetes. When PTP1B gene was deleted selectively in the brain of mice, the major effects on weight and glucose control were consistent with the whole body deletion of PTP1B. This is in contrast to the muscle-, liver-, and adipocyte-specific deletion, which had no beneficial effects on obesity. While these results indicate the importance of neuronal PTP1B in maintaining energy homeostasis, the peripheral PTP1B is also being investigated for their potential roles in the control of energy balance. Validation of PTP1B as a therapeutic target for obesity and diabetes prompted efforts to develop potent and selective inhibitors of PTP1B. Among the small molecule inhibitors investigated, trodusquemine, which acts both centrally and peripherally, is currently in phase 2 clinical trials. An approach using PTP1B-directed antisense oligonucleotides is also in phase 2 clinical trials.
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Affiliation(s)
- Hyeongjin Cho
- Department of Chemistry, Inha University, Incheon, Korea.
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22
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Bowers J, Terrien J, Clerget-Froidevaux MS, Gothié JD, Rozing MP, Westendorp RGJ, van Heemst D, Demeneix BA. Thyroid hormone signaling and homeostasis during aging. Endocr Rev 2013; 34:556-89. [PMID: 23696256 DOI: 10.1210/er.2012-1056] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Studies in humans and in animal models show negative correlations between thyroid hormone (TH) levels and longevity. TH signaling is implicated in maintaining and integrating metabolic homeostasis at multiple levels, notably centrally in the hypothalamus but also in peripheral tissues. The question is thus raised of how TH signaling is modulated during aging in different tissues. Classically, TH actions on mitochondria and heat production are obvious candidates to link negative effects of TH to aging. Mitochondrial effects of excess TH include reactive oxygen species and DNA damage, 2 factors often considered as aging accelerators. Inversely, caloric restriction, which can retard aging from nematodes to primates, causes a rapid reduction of circulating TH, reducing metabolism in birds and mammals. However, many other factors could link TH to aging, and it is these potentially subtler and less explored areas that are highlighted here. For example, effects of TH on membrane composition, inflammatory responses, stem cell renewal and synchronization of physiological responses to light could each contribute to TH regulation of maintenance of homeostasis during aging. We propose the hypothesis that constraints on TH signaling at certain life stages, notably during maturity, are advantageous for optimal aging.
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Affiliation(s)
- J Bowers
- Muséum national d'Histoire Naturelle, Laboratoire de Physiologie Générale et Comparée, Unité Mixte de Recherche, Centre National de la Recherche Scientifique 7221, 75231 Paris cedex 5, France
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23
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Tsou RC, Bence KK. Central regulation of metabolism by protein tyrosine phosphatases. Front Neurosci 2013; 6:192. [PMID: 23308070 PMCID: PMC3538333 DOI: 10.3389/fnins.2012.00192] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 12/17/2012] [Indexed: 11/13/2022] Open
Abstract
Protein tyrosine phosphatases (PTPs) are important regulators of intracellular signaling pathways via the dephosphorylation of phosphotyrosyl residues on various receptor and non-receptor substrates. The phosphorylation state of central nervous system (CNS) signaling components underlies the molecular mechanisms of a variety of physiological functions including the control of energy balance and glucose homeostasis. In this review, we summarize the current evidence implicating PTPs as central regulators of metabolism, specifically highlighting their interactions with the neuronal leptin and insulin signaling pathways. We discuss the role of a number of PTPs (PTP1B, SHP2, TCPTP, RPTPe, and PTEN), reviewing the findings from genetic mouse models and in vitro studies which highlight these phosphatases as key central regulators of energy homeostasis.
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Affiliation(s)
- Ryan C Tsou
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania Philadelphia, PA, USA
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24
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Marino JS, Iler J, Dowling AR, Chua S, Bruning JC, Coppari R, Hill JW. Adipocyte dysfunction in a mouse model of polycystic ovary syndrome (PCOS): evidence of adipocyte hypertrophy and tissue-specific inflammation. PLoS One 2012; 7:e48643. [PMID: 23119079 PMCID: PMC3485364 DOI: 10.1371/journal.pone.0048643] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 09/27/2012] [Indexed: 02/06/2023] Open
Abstract
Clinical research shows an association between polycystic ovary syndrome (PCOS) and chronic inflammation, a pathological state thought to contribute to insulin resistance. The underlying pathways, however, have not been defined. The purpose of this study was to characterize the inflammatory state of a novel mouse model of PCOS. Female mice lacking leptin and insulin receptors in pro-opiomelanocortin neurons (IR/LepR(POMC) mice) and littermate controls were evaluated for estrous cyclicity, ovarian and adipose tissue morphology, and body composition by QMR and CT scan. Tissue-specific macrophage infiltration and cytokine mRNA expression were measured, as well as circulating cytokine levels. Finally, glucose regulation during pregnancy was evaluated as a measure of risk for diabetes development. Forty-five percent of IR/LepR(POMC) mice showed reduced or absent ovulation. IR/LepR(POMC) mice also had increased fat mass and adipocyte hypertrophy. These traits accompanied elevations in macrophage accumulation and inflammatory cytokine production in perigonadal adipose tissue, liver, and ovary. These mice also exhibited gestational hyperglycemia as predicted. This report is the first to show the presence of inflammation in IR/LepR(POMC) mice, which develop a PCOS-like phenotype. Thus, IR/LepR(POMC) mice may serve as a new mouse model to clarify the involvement of adipose and liver tissue in the pathogenesis and etiology of PCOS, allowing more targeted research on the development of PCOS and potential therapeutic interventions.
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Affiliation(s)
- Joseph S. Marino
- Department of Physiology and Pharmacology, Center for Diabetes and Endocrine Research, University of Toledo Medical Center, Toledo, Ohio, United States of America
| | - Jeffrey Iler
- Department of Physiology and Pharmacology, Center for Diabetes and Endocrine Research, University of Toledo Medical Center, Toledo, Ohio, United States of America
| | - Abigail R. Dowling
- Department of Physiology and Pharmacology, Center for Diabetes and Endocrine Research, University of Toledo Medical Center, Toledo, Ohio, United States of America
| | - Streamson Chua
- Departments of Medicine and Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Jens C. Bruning
- Department of Mouse Genetics and Metabolism, Institute for Genetics, Cologne Excellence Cluster for Cellular Stress Responses in Aging Associated Diseases, and Center for Molecular Medicine Cologne, 2nd Department for Internal Medicine, University of Cologne, and Max Planck Institute for the Biology of Aging, Cologne, Germany
| | - Roberto Coppari
- Departments of Internal Medicine, Division of Hypothalamic Research, Pharmacology, and Psychiatry, The University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Jennifer W. Hill
- Department of Physiology and Pharmacology, Center for Diabetes and Endocrine Research, University of Toledo Medical Center, Toledo, Ohio, United States of America
- Department of Obstetrics-Gynecology, University of Toledo Medical Center, Toledo, Ohio, United States of America
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25
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De Jonghe BC, Hayes MR, Zimmer DJ, Kanoski SE, Grill HJ, Bence KK. Food intake reductions and increases in energetic responses by hindbrain leptin and melanotan II are enhanced in mice with POMC-specific PTP1B deficiency. Am J Physiol Endocrinol Metab 2012; 303:E644-51. [PMID: 22761160 PMCID: PMC3468506 DOI: 10.1152/ajpendo.00009.2012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Leptin regulates energy balance through central circuits that control food intake and energy expenditure, including proopiomelanocortin (POMC) neurons. POMC neuron-specific deletion of protein tyrosine phosphatase 1B (PTP1B) (Ptpn1(loxP/loxP) POMC-Cre), a negative regulator of CNS leptin signaling, results in resistance to diet-induced obesity and improved peripheral leptin sensitivity in mice, thus establishing PTP1B as an important component of POMC neuron regulation of energy balance. POMC neurons are expressed in the pituitary, the arcuate nucleus of the hypothalamus (ARH), and the nucleus of the solitary tract (NTS) in the hindbrain, and it is unknown how each population might contribute to the phenotype of POMC-Ptp1b(-/-) mice. It is also unknown whether improved leptin sensitivity in POMC-Ptp1b(-/-) mice involves altered melanocortin receptor signaling. Therefore, we examined the effects of hindbrain administration (4th ventricle) of leptin (1.5, 3, and 6 μg) or the melanocortin 3/4R agonist melanotan II (0.1 and 0.2 nmol) in POMC-Ptp1b(-/-) (KO) and control PTP1B(fl/fl) (WT) mice on food intake, body weight, spontaneous physical activity (SPA), and core temperature (T(C)). The results show that KO mice were hypersensitive to hindbrain leptin- and MTII-induced food intake and body weight suppression and SPA compared with WT mice. Greater increases in leptin- but not MTII-induced T(C) were also observed in KO vs. WT animals. In addition, KO mice displayed elevated hindbrain and hypothalamic MC4R mRNA expression. These studies are the first to show that hindbrain administration of leptin or a melanocortin receptor agonist alters energy balance in mice likely via participation of hindbrain POMC neurons.
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MESH Headings
- Animals
- Appetite Depressants/administration & dosage
- Appetite Depressants/pharmacology
- Appetite Regulation/drug effects
- Dose-Response Relationship, Drug
- Energy Metabolism/drug effects
- Female
- Gene Expression Regulation/drug effects
- Injections, Intraventricular
- Leptin/administration & dosage
- Leptin/metabolism
- Male
- Mice
- Mice, Knockout
- Nerve Tissue Proteins/agonists
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Neurons/drug effects
- Neurons/metabolism
- Organ Specificity
- Peptides, Cyclic/administration & dosage
- Peptides, Cyclic/pharmacology
- Pro-Opiomelanocortin/metabolism
- Protein Tyrosine Phosphatase, Non-Receptor Type 1/deficiency
- Protein Tyrosine Phosphatase, Non-Receptor Type 1/genetics
- Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism
- RNA, Messenger/metabolism
- Receptor, Melanocortin, Type 3/agonists
- Receptor, Melanocortin, Type 4/agonists
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Rhombencephalon/drug effects
- Rhombencephalon/metabolism
- alpha-MSH/administration & dosage
- alpha-MSH/analogs & derivatives
- alpha-MSH/pharmacology
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Affiliation(s)
- Bart C De Jonghe
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia PA, USA
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